The present invention relates to a hybrid with a balancing network for connecting a transmitter and a receiver to a two-wire line for full-duplex transmission of digital signals.
Such hybrids are known and may contain transformers or comprise mainly resistors. German Published Pat. application (DT-AS) No. 2,454,108 discloses a resistance bridge hybrid circuit by means of which the transmitter and the receiver are connected to the terminal stations of the two-wire line. One bridge resistance is the input impedance of the two-wire line, and another bridge resistance is the opposite balancing network. To provide optimum isolation between the transmitter and the receiver of the same terminal station so that the terminal's own receiver will not be disturbed while the transmitter is in operation, the line and its balancing network must be matched as accurately as possible. In the known hybrid, this is done by means of an expensive variable balancing network which is manually adjustable for balancing the bridge circuit.